The Cancer Pain-assessment Toolkit for Use in RoutinE oncology outpatient services (CAPTURE) study is a three-phase study funded by Yorkshire Cancer Research. First, we undertook a detailed qualitative evaluation of existing pain management processes at tertiary oncology referral centres in the UK.9 In phase two, we adapted the Edinburgh Pain Assessment and Management Tool (EPAT)12 for use in routine OOS, using a theoretically informed approach to complex intervention adaptation.13 14 The third phase is a multicentre cluster-randomised pilot trial. The trial aims to establish the feasibility of undertaking a definitive phase III multicentre cluster randomised trial within the UK National Health Service (NHS). This trial includes an embedded process evaluation which aims to evaluate the acceptability, fidelity and implementation of the intervention and trial procedures.

In its original form, EPAT12 was designed to prompt clinicians on oncology inpatient wards to systematically assess and manage cancer pain across the duration of a care episode. Pain scores were used to guide clinical decision-making and treatment using linked treatment algorithms. EPAT consists of four core components: (1) pain intensity screening, (2) detailed pain assessment, (3) treatment planning and (4) reassessment. These four core intervention components were designed to be integrated within existing routine care pathways on hospital oncology wards. Pain intensity screening (component one) was integrated within the patients’ vital-signs charts and completed hourly alongside other vital sign assessments (eg, blood pressure, temperature, pulse rate). If patients reported pain of 3 or greater (out of 10), this prompted a doctor or nurse to complete a detailed assessment of pain aetiology, mechanisms and impact (component two), resulting in a treatment plan (component three). Pain intensity and response to treatment were monitored as part of the vital-signs hourly reassessment (component four). To facilitate the implementation of EPAT within ‘normal practice’ (ie, support behaviour change), EPAT was integrated within ward policy and standard operating procedures, and all staff working on EPAT wards were trained in its use. Standard operating procedures and training materials described healthcare professionals (HCPs) undertaking intervention components as ‘intervention deliverers’ and patients with cancer reporting pain as ‘intervention receivers’. Additionally, an EPAT champion was identified at each ward to facilitate staff training, monitor EPAT use (ie, fidelity) and deliver additional ‘top-up’ training where necessary.

In order for EPAT to fit within the new context (oncology outpatient settings), we undertook a theoretically informed systematic adaptation of EPAT.15 We undertook a series of qualitative interviews (phase 1). We conducted codesign workshops with oncology outpatient HCPs and systematically deconstructed the intervention, identified the core and peripheral components and reconstructed the intervention to fit within oncology outpatient settings (phase 2).15 The adaptation process was supported by three expert panels: (1) experts by lived experience, (2) experts by clinical experience and (3) experts by academic experience who cofacilitated the workshops and supported the research team to evaluate and integrate workshop outcomes into the adapted version of EPAT, which is subsequently referred to as EPAT+.

The final prototype intervention (EPAT+) was adapted to support pain management for individuals living with cancer who are being cared for at OOS; EPAT+addresses treatment-related cancer, tumour-related cancer pain, as well as non-malignant causes of chronic pain in patients with cancer.15 An outline of the core components of EPAT+ and the modifications made to the intervention are published elsewhere.15

The final phase of the CAPTURE study is a multicentre cluster randomised pilot trial. 12 outpatient services from 2 NHS tertiary oncology referral centres in the North of England will be randomly allocated (1:1) to deliver EPAT+in addition to usual care or usual care alone. It is anticipated that usual care will consist of appropriate individual pain assessment by nursing and medical staff, followed by a management decision. At present in the UK, this part of cancer care is not carried out in a structured, systematic fashion. While pharmacological management is based on the principles of WHO guidelines, the way in which these guidelines are used is not standardised.

A formal power calculation is not required for this feasibility study, as it is not designed to estimate effectiveness. Teare et al recommend16 that external feasibility trials include at least 60 participants per arm when the primary outcome is binary. Allowing for a 30% loss to follow-up and rounding to ensure balance across clinics (15 participants per clinic across 12 clinics), a total sample size of 180 participants (90 per arm) is deemed sufficient to meet the study objectives. Thus, 180 eligible patients will be recruited. An embedded process evaluation will assess acceptability, fidelity and intervention implementation. Process evaluations offer insights into implementation variation, resource use, participant roles, contextual factors and their impact on outcomes.17 Pilot trials commonly evaluate feasibility, acceptability and fidelity of the trial methods and intervention, aligning with Medical Research Council (MRC) guidance.14 18 This helps researchers to systematically evaluate intervention design, address practical challenges and understand acceptability to participants and those delivering the intervention, supporting refinements before a larger trial.

Assessing intervention acceptability has become essential in healthcare design and implementation due to the involvement of multiple intervention components for both deliverers (eg, HCPs) and recipients (eg, participants).18 19 A theoretical acceptability framework explores intervention acceptability across seven components: affective attitude, burden, perceived effectiveness, ethicality, intervention coherence, opportunity costs and self-efficacy.19 The CAPTURE pilot trial will enable the acceptability of EPAT+ to be explored on a large scale, with intervention components evaluated by both those that deliver them and those that receive them.

Intervention fidelity refers to how closely an intervention is implemented as intended, potentially moderating the relationship between the intervention and its outcomes.20 21 It includes measurable quantitative and qualitative aspects across five dimensions: adherence, dosage, quality of delivery, participant responsiveness and programme differentiation. Assessing fidelity across these levels enhances fidelity itself, supporting both the internal and external validity of larger trials.

This protocol paper will focus specifically on the embedded process evaluation. There will be a separate paper that presents the protocol for the multicluster randomised pilot trial. This process evaluation has two aims: (1) to assess fidelity of intervention component delivery within OOS settings and (2) to understand the acceptability of the intervention components and trial processes to those delivering and receiving the intervention. These two aims address the implementation and contextual factors described in the MRC framework for process evaluation of complex interventions.18

The specific objectives for each aim are:

A multicentre, two-arm, pilot cluster randomised controlled trial, comparing EPAT+ (intervention) with usual care from at least two NHS tertiary oncology referral centres (sites) in the North of England. The cluster pilot trial protocol is described in detail elsewhere22; however, in brief, the structure of the trial clusters has been designed to capture variation in oncology outpatient clinics by centre type (eg, tertiary referral centre, district general hospital), staffing background (eg, oncologist, nurse, clinical support worker) and clinic process nature (eg, single or multiple consultants-led clinics).

Eligible patients approached regarding study participation, and those consenting will complete three follow-ups, at 1 week, 1 month and 2 months. Data collected from a mix of patient-reported questionnaires (available online or paper formats), and data extracted from electronic health records.

We will use qualitative and quantitative methods to address the process evaluation aims, embedded within the CAPTURE pilot trial. The process evaluation will involve assessment with four participant groups:

1. Intervention champions (HCPs at site that lead implementation of the intervention).

2. RNs involved in trial research activities.

Patient-participants, RNs and HCPs will be recruited from both trial arms.

The process evaluation aims will be delivered by capturing data for each objective in the following way:

At the project’s outset, we established a patient and public involvement and engagement (PPIE) group, comprising individuals with personal experience of managing cancer pain and a former caregiver. One PPIE member also joined the research team as a grant coapplicant. The group met during the study development phase and contributed to the design and proposed trial delivery methods.

Semistructured interviews will be conducted to assess fidelity and quality of intervention implementation and identify the contextual factors that are associated with any variation in intervention uptake, outcome measures and trial processes. Interviews will be conducted with patient-participants (from both intervention and usual care arms), intervention champions and HCPs (from both intervention and usual care arms) in OOS and RNs that were involved in trial research activities. Interviews will last up to 1 hour.

Interview topic guides for participant groups have been developed by the research team in line with the framework of acceptability19 and previous literature.12 An adapted framework of acceptability will guide the questions used to explore the acceptability of EPAT+ (figure 1). Interviews will be conducted via telephone, videoconferencing software (eg, Microsoft Teams) or in-person at site. Interviews will be recorded using either an audio recorder (in case of telephone or in-person interviews) or using the recording function via videoconferencing software. All video or audio files of interviews will be deleted once the interview has been transcribed verbatim and analysed (in case recordings need to be returned to during analysis to check meaning or accuracy). Transcription and analysis will be done by the University of Leeds research team.

The study opened for recruitment on 4 December 2023 and was open at the time of submission.

Not applicable.